From 17c2782a4d2977a026f7652f62b8fe0841779807 Mon Sep 17 00:00:00 2001
From: Antoine van Gelder <antoine@greatscottgadgets.com>
Date: Mon, 1 Jun 2026 14:39:45 +0200
Subject: [PATCH 1/7] radio: Add support for locking radio registers

---
 firmware/common/radio.c                | 24 ++++++++++
 firmware/common/radio.h                | 11 +++++
 firmware/hackrf_usb/hackrf_usb.c       |  1 +
 firmware/hackrf_usb/usb_api_register.c | 17 +++++++
 firmware/hackrf_usb/usb_api_register.h |  3 ++
 firmware/hackrf_usb/usb_descriptor.c   |  2 +-
 host/hackrf-tools/src/hackrf_debug.c   | 65 ++++++++++++++++++++++++--
 host/libhackrf/src/hackrf.c            | 28 +++++++++++
 host/libhackrf/src/hackrf.h            | 14 ++++++
 9 files changed, 159 insertions(+), 6 deletions(-)

diff --git a/firmware/common/radio.c b/firmware/common/radio.c
index f8b2e5141..3dd997d63 100644
--- a/firmware/common/radio.c
+++ b/firmware/common/radio.c
@@ -59,6 +59,7 @@ void radio_init(radio_t* const radio)
 	radio->config[RADIO_BANK_TX][RADIO_OPMODE] = TRANSCEIVER_MODE_TX;
 	radio->config[RADIO_BANK_IDLE][RADIO_BIAS_TEE] = false;
 	radio->regs_dirty = 0;
+	radio->regs_locked = 0;
 }
 
 static inline void mark_dirty(radio_t* const radio, radio_register_t reg)
@@ -66,6 +67,11 @@ static inline void mark_dirty(radio_t* const radio, radio_register_t reg)
 	radio->regs_dirty |= (1 << reg);
 }
 
+static inline bool check_locked(radio_t* const radio, radio_register_t reg)
+{
+	return radio->regs_locked & (1 << reg);
+}
+
 radio_error_t radio_reg_write(
 	radio_t* const radio,
 	const radio_register_bank_t bank,
@@ -76,6 +82,10 @@ radio_error_t radio_reg_write(
 		return RADIO_ERR_INVALID_REGISTER;
 	}
 
+	if (check_locked(radio, reg)) {
+		return RADIO_ERR_LOCKED_REGISTER;
+	}
+
 	switch (bank) {
 	case RADIO_BANK_ACTIVE:
 		mark_dirty(radio, reg);
@@ -106,6 +116,20 @@ uint64_t radio_reg_read(
 	return radio->config[bank][reg];
 }
 
+radio_error_t radio_reg_lock(
+	radio_t* const radio,
+	const radio_register_t reg,
+	const bool locked)
+{
+	if (reg > RADIO_NUM_REGS) {
+		return RADIO_ERR_INVALID_REGISTER;
+	}
+
+	radio->regs_locked = (radio->regs_locked & ~(1 << reg)) | (locked << reg);
+
+	return RADIO_OK;
+}
+
 static uint32_t radio_update_direction(radio_t* const radio, uint64_t* bank)
 {
 	const uint64_t requested = bank[RADIO_OPMODE];
diff --git a/firmware/common/radio.h b/firmware/common/radio.h
index 821c7fead..6724ad4a7 100644
--- a/firmware/common/radio.h
+++ b/firmware/common/radio.h
@@ -34,6 +34,7 @@ typedef enum {
 	RADIO_ERR_INVALID_PARAM = -2,
 	RADIO_ERR_INVALID_BANK = -3,
 	RADIO_ERR_INVALID_REGISTER = -4,
+	RADIO_ERR_LOCKED_REGISTER = -5,
 	RADIO_ERR_UNSUPPORTED_OPERATION = -10,
 	RADIO_ERR_UNIMPLEMENTED = -19,
 	RADIO_ERR_OTHER = -9999,
@@ -225,6 +226,7 @@ typedef struct {
 	radio_config_mode_t config_mode;
 	uint64_t config[RADIO_NUM_BANKS][RADIO_NUM_REGS];
 	volatile uint32_t regs_dirty;
+	uint32_t regs_locked;
 	update_fn update_cb;
 } radio_t;
 
@@ -248,6 +250,15 @@ uint64_t radio_reg_read(
 	const radio_register_bank_t bank,
 	const radio_register_t reg);
 
+/**
+ * Lock a register. Prevents any future calls to `radio_reg_write`
+ * from overwriting the current stored value of the register.
+ */
+radio_error_t radio_reg_lock(
+	radio_t* const radio,
+	const radio_register_t reg,
+	const bool locked);
+
 /**
  * Apply changes requested in RADIO_BANK_ACTIVE.
  * Return true if any changes were applied.
diff --git a/firmware/hackrf_usb/hackrf_usb.c b/firmware/hackrf_usb/hackrf_usb.c
index 813a94539..4cdfbd14e 100644
--- a/firmware/hackrf_usb/hackrf_usb.c
+++ b/firmware/hackrf_usb/hackrf_usb.c
@@ -182,6 +182,7 @@ static usb_request_handler_fn vendor_request_handler[] = {
 	usb_vendor_request_write_radio_reg,
 	usb_vendor_request_read_radio_reg,
 	usb_vendor_request_get_buffer_size,
+	usb_vendor_request_lock_radio_reg,
 };
 
 static const uint32_t vendor_request_handler_count =
diff --git a/firmware/hackrf_usb/usb_api_register.c b/firmware/hackrf_usb/usb_api_register.c
index 626c75089..a46a22404 100644
--- a/firmware/hackrf_usb/usb_api_register.c
+++ b/firmware/hackrf_usb/usb_api_register.c
@@ -416,3 +416,20 @@ usb_request_status_t usb_vendor_request_read_radio_reg(
 	}
 	return USB_REQUEST_STATUS_OK;
 }
+
+usb_request_status_t usb_vendor_request_lock_radio_reg(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage)
+{
+	if (stage == USB_TRANSFER_STAGE_SETUP) {
+		uint8_t reg = endpoint->setup.index;
+		bool locked = endpoint->setup.value != 0 ? true : false;
+		if (reg >= RADIO_NUM_REGS) {
+			return USB_REQUEST_STATUS_STALL;
+		}
+		radio_reg_lock(&radio, reg, locked);
+		usb_transfer_schedule_ack(endpoint->in);
+	}
+
+	return USB_REQUEST_STATUS_OK;
+}
diff --git a/firmware/hackrf_usb/usb_api_register.h b/firmware/hackrf_usb/usb_api_register.h
index a5a36550d..7e434c1a7 100644
--- a/firmware/hackrf_usb/usb_api_register.h
+++ b/firmware/hackrf_usb/usb_api_register.h
@@ -70,3 +70,6 @@ usb_request_status_t usb_vendor_request_write_radio_reg(
 usb_request_status_t usb_vendor_request_read_radio_reg(
 	usb_endpoint_t* const endpoint,
 	const usb_transfer_stage_t stage);
+usb_request_status_t usb_vendor_request_lock_radio_reg(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage);
diff --git a/firmware/hackrf_usb/usb_descriptor.c b/firmware/hackrf_usb/usb_descriptor.c
index 005babb35..dde22e6e3 100644
--- a/firmware/hackrf_usb/usb_descriptor.c
+++ b/firmware/hackrf_usb/usb_descriptor.c
@@ -28,7 +28,7 @@
 
 #define USB_VENDOR_ID (0x1D50)
 
-#define USB_API_VERSION (0x0112)
+#define USB_API_VERSION (0x0113)
 
 #define USB_WORD(x) (x & 0xFF), ((x >> 8) & 0xFF)
 
diff --git a/host/hackrf-tools/src/hackrf_debug.c b/host/hackrf-tools/src/hackrf_debug.c
index 52ede9cb7..49bc31ed1 100644
--- a/host/hackrf-tools/src/hackrf_debug.c
+++ b/host/hackrf-tools/src/hackrf_debug.c
@@ -545,6 +545,30 @@ int radio_write_register(
 	return result;
 }
 
+int radio_lock_register(
+	hackrf_device* device,
+	const uint16_t register_number,
+	const bool register_locked)
+{
+	int result = HACKRF_SUCCESS;
+	result = hackrf_radio_lock_register(
+		device,
+		(uint8_t) register_number,
+		register_locked);
+
+	if (result == HACKRF_SUCCESS) {
+		printf("register [%2d] -> %s\n",
+		       register_number,
+		       register_locked ? "locked" : "unlocked");
+	} else {
+		printf("hackrf_radio_lock_register() failed: %s (%d)\n",
+		       hackrf_error_name(result),
+		       result);
+	}
+
+	return result;
+}
+
 int read_register(
 	hackrf_device* device,
 	uint8_t part,
@@ -621,6 +645,20 @@ int write_register(
 	return HACKRF_ERROR_INVALID_PARAM;
 }
 
+int lock_register(
+	hackrf_device* device,
+	uint8_t part,
+	const uint16_t register_number,
+	const bool register_locked)
+{
+	switch (part) {
+	case PART_RADIO:
+		return radio_lock_register(device, register_number, register_locked);
+	default:
+		return HACKRF_ERROR_INVALID_PARAM;
+	}
+}
+
 static const char* mode_name(uint32_t mode)
 {
 	const char* mode_names[] = {"IDLE", "WAIT", "RX", "TX_START", "TX_RUN"};
@@ -675,6 +713,7 @@ static void usage()
 	printf("\t-n, --register <n>: set register number for read/write operations\n");
 	printf("\t-r, --read: read register specified by last -n argument, or all registers\n");
 	printf("\t-w, --write <v>: write register specified by last -n argument with value <v>\n");
+	printf("\t-L, --lock <state>: lock register specified by last -n argument (0 for unlocked, 1 for locked)\n");
 	printf("\t-c, --config: print SI5351C multisynth configuration information\n");
 	printf("\t-d, --device <s>: specify a particular device by serial number\n");
 	printf("\t-m, --max283x: target MAX283x\n");
@@ -709,6 +748,7 @@ static struct option long_options[] = {
 	{"register", required_argument, 0, 'n'},
 	{"write", required_argument, 0, 'w'},
 	{"read", no_argument, 0, 'r'},
+	{"lock", required_argument, 0, 'L'},
 	{"device", required_argument, 0, 'd'},
 	{"help", no_argument, 0, 'h'},
 	{"max2837", no_argument, 0, 'm'},
@@ -740,10 +780,12 @@ int main(int argc, char** argv)
 	int bank = -1;
 	uint64_t register_number = REGISTER_INVALID;
 	uint64_t register_value;
+	uint64_t register_locked;
 	hackrf_device* device = NULL;
 	int option_index = 0;
 	bool read = false;
 	bool write = false;
+	bool lock = false;
 	bool dump_config = false;
 	bool dump_state = false;
 	uint8_t part = PART_NONE;
@@ -782,7 +824,7 @@ int main(int argc, char** argv)
 	while ((opt = getopt_long(
 			argc,
 			argv,
-			"b:n:rw:d:cmsfgi1:2:C:N:P:ST:R:h?u:l:ta:o",
+			"b:n:rw:l:d:cmsfgi1:2:C:N:P:ST:R:h?u:l:ta:o",
 			long_options,
 			&option_index)) != EOF) {
 		switch (opt) {
@@ -805,6 +847,11 @@ int main(int argc, char** argv)
 			read = true;
 			break;
 
+		case 'L':
+			lock = true;
+			result = parse_int(optarg, &register_locked);
+			break;
+
 		case 'c':
 			dump_config = true;
 			break;
@@ -931,8 +978,8 @@ int main(int argc, char** argv)
 		}
 	}
 
-	if (write && read) {
-		fprintf(stderr, "Read and write options are mutually exclusive.\n");
+	if ((write && read) || (lock && write) || (lock && read)) {
+		fprintf(stderr, "Read, write and lock options are mutually exclusive.\n");
 		usage();
 		return EXIT_FAILURE;
 	}
@@ -949,6 +996,10 @@ int main(int argc, char** argv)
 		return EXIT_FAILURE;
 	}
 
+	if (lock && part != PART_RADIO) {
+		fprintf(stderr, "Lock option is only valid for radio.\n");
+	}
+
 	if ((bank > -1) && (part != PART_RADIO)) {
 		fprintf(stderr, "Bank valid only for radio.\n");
 		usage();
@@ -959,11 +1010,11 @@ int main(int argc, char** argv)
 		bank = 0;
 	}
 
-	if (!(write || read || dump_config || dump_state || set_tx_limit ||
+	if (!(write || read || lock || dump_config || dump_state || set_tx_limit ||
 	      set_rx_limit || set_ui || set_leds || set_p1 || set_p2 || set_clkin ||
 	      set_narrowband || set_fpga_bitstream || read_selftest || test_rtc_osc ||
 	      read_adc)) {
-		fprintf(stderr, "Specify read, write, or config option.\n");
+		fprintf(stderr, "Specify read, write, lock, or config option.\n");
 		usage();
 		return EXIT_FAILURE;
 	}
@@ -1016,6 +1067,10 @@ int main(int argc, char** argv)
 		}
 	}
 
+	if (lock) {
+		result = lock_register(device, part, register_number, register_locked);
+	}
+
 	if (dump_config) {
 		si5351c_read_configuration(device);
 	}
diff --git a/host/libhackrf/src/hackrf.c b/host/libhackrf/src/hackrf.c
index 7bafd5f39..a3b90163f 100644
--- a/host/libhackrf/src/hackrf.c
+++ b/host/libhackrf/src/hackrf.c
@@ -120,6 +120,7 @@ typedef enum {
 	HACKRF_VENDOR_REQUEST_RADIO_WRITE_REG = 59,
 	HACKRF_VENDOR_REQUEST_RADIO_READ_REG = 60,
 	HACKRF_VENDOR_REQUEST_GET_BUFFER_SIZE = 61,
+	HACKRF_VENDOR_REQUEST_RADIO_LOCK_REG = 62,
 } hackrf_vendor_request;
 
 #define USB_CONFIG_STANDARD 0x1
@@ -3574,6 +3575,33 @@ int ADDCALL hackrf_radio_write_register(
 	}
 }
 
+int ADDCALL hackrf_radio_lock_register(
+	hackrf_device* device,
+	const uint8_t register_number,
+	const bool register_locked)
+{
+	USB_API_REQUIRED(device, 0x0113);
+	int result;
+
+	result = libusb_control_transfer(
+		device->usb_device,
+		LIBUSB_ENDPOINT_OUT | LIBUSB_REQUEST_TYPE_VENDOR |
+			LIBUSB_RECIPIENT_DEVICE,
+		HACKRF_VENDOR_REQUEST_RADIO_LOCK_REG,
+		register_locked,
+		register_number,
+		NULL,
+		0,
+		DEFAULT_REQUEST_TIMEOUT);
+
+	if (result != 0) {
+		last_libusb_error = result;
+		return HACKRF_ERROR_LIBUSB;
+	}
+
+	return HACKRF_SUCCESS;
+}
+
 #ifdef __cplusplus
 } // __cplusplus defined.
 #endif
diff --git a/host/libhackrf/src/hackrf.h b/host/libhackrf/src/hackrf.h
index eeca65e03..6cf71dd91 100644
--- a/host/libhackrf/src/hackrf.h
+++ b/host/libhackrf/src/hackrf.h
@@ -2385,6 +2385,20 @@ extern ADDAPI int ADDCALL hackrf_radio_write_register(
 	const uint8_t register_number,
 	const uint64_t value);
 
+/**
+ * Lock or unlock a radio configuration register.
+ *
+ * @param[in] device device to write
+ * @param[in] register_number register number to mask
+ * @param[out] locked locked state for the register
+ * @return @ref HACKRF_SUCCESS on success or @ref hackrf_error variant
+ * @ingroup debug
+ */
+extern ADDAPI int ADDCALL hackrf_radio_lock_register(
+	hackrf_device* device,
+	const uint8_t register_number,
+	const bool register_locked);
+
 #ifdef __cplusplus
 } // __cplusplus defined.
 #endif

From 335fd6a99e8d23994291e6c088fef7fb556124b8 Mon Sep 17 00:00:00 2001
From: Antoine van Gelder <antoine@greatscottgadgets.com>
Date: Wed, 24 Jun 2026 11:01:46 +0200
Subject: [PATCH 2/7] radio: add radio_set_config_mode()

---
 firmware/common/fpga.h  |  8 +++++
 firmware/common/radio.c | 67 +++++++++++++++++++++++++++++++++++++++++
 firmware/common/radio.h |  9 ++++++
 3 files changed, 84 insertions(+)

diff --git a/firmware/common/fpga.h b/firmware/common/fpga.h
index 1765fcdd1..58152e687 100644
--- a/firmware/common/fpga.h
+++ b/firmware/common/fpga.h
@@ -26,6 +26,14 @@
 
 #include "ice40_spi.h"
 
+/* Supported Bitstreams. */
+typedef enum {
+	FPGA_BITSTREAM_STANDARD = 0,
+	FPGA_BITSTREAM_HALFPREC = 1,
+	FPGA_BITSTREAM_EXTPREC_RX = 2,
+	FPGA_BITSTREAM_EXTPREC_TX = 3,
+} fpga_bitstream_index_t;
+
 /* Up to 7 registers, each containing up to 8 bits of data */
 #define FPGA_NUM_REGS            7
 #define FPGA_DATA_REGS_MAX_VALUE 255
diff --git a/firmware/common/radio.c b/firmware/common/radio.c
index 3dd997d63..9755a02db 100644
--- a/firmware/common/radio.c
+++ b/firmware/common/radio.c
@@ -952,3 +952,70 @@ void radio_switch_opmode(radio_t* const radio, const transceiver_mode_t mode)
 	nvic_enable_irq(NVIC_USB0_IRQ);
 	radio_update(radio);
 }
+
+bool radio_set_config_mode(radio_t* const radio, const radio_config_mode_t mode)
+{
+	// Check if the requested mode is supported.
+	switch (mode) {
+	case RADIO_CONFIG_LEGACY:
+	case RADIO_CONFIG_STANDARD:
+		// supported on all boards
+		break;
+#ifdef IS_PRALINE
+	case RADIO_CONFIG_HALF_PRECISION:
+	case RADIO_CONFIG_EXT_PRECISION_RX:
+	case RADIO_CONFIG_EXT_PRECISION_TX:
+		// only supported on praline
+		if (!IS_PRALINE) {
+			return false;
+		}
+		break;
+#endif
+	default:
+		return false;
+	}
+
+	// Don't do anything if we're already in the requested mode.
+	if (mode == radio->config_mode) {
+		return true;
+	}
+
+#if defined(IS_PRALINE) && !(defined(DFU_MODE) || defined(RAM_MODE))
+	if (IS_PRALINE) {
+		fpga_bitstream_index_t bitstream_index;
+		switch (mode) {
+		case RADIO_CONFIG_LEGACY:
+		case RADIO_CONFIG_STANDARD:
+			bitstream_index = FPGA_BITSTREAM_STANDARD;
+			break;
+		case RADIO_CONFIG_HALF_PRECISION:
+			bitstream_index = FPGA_BITSTREAM_HALFPREC;
+			break;
+		case RADIO_CONFIG_EXT_PRECISION_RX:
+			bitstream_index = FPGA_BITSTREAM_EXTPREC_RX;
+			break;
+		case RADIO_CONFIG_EXT_PRECISION_TX:
+			bitstream_index = FPGA_BITSTREAM_EXTPREC_TX;
+			break;
+		default:
+			return false;
+		}
+
+		// Reset radio state.
+		for (uint8_t reg = 0; reg < RADIO_NUM_REGS; reg++) {
+			radio_reg_write(radio, RADIO_BANK_ALL, reg, RADIO_UNSET);
+		}
+
+		// Load bitstream.
+		extern struct fpga_loader_t fpga_loader;
+		if (!fpga_image_load(&fpga_loader, bitstream_index)) {
+			return false;
+		}
+	}
+#endif
+
+	// Update radio config mode.
+	radio->config_mode = mode;
+
+	return true;
+}
diff --git a/firmware/common/radio.h b/firmware/common/radio.h
index 6724ad4a7..ba4ced388 100644
--- a/firmware/common/radio.h
+++ b/firmware/common/radio.h
@@ -41,12 +41,15 @@ typedef enum {
 } radio_error_t;
 
 /* radio configuration modes */
+// TODO are we sure we need a legacy mode?
 typedef enum {
 	RADIO_CONFIG_LEGACY = 0,
 	RADIO_CONFIG_STANDARD = 1,
+#ifdef IS_PRALINE
 	RADIO_CONFIG_EXT_PRECISION_RX = 2,
 	RADIO_CONFIG_EXT_PRECISION_TX = 3,
 	RADIO_CONFIG_HALF_PRECISION = 4,
+#endif
 } radio_config_mode_t;
 
 typedef struct {
@@ -271,6 +274,12 @@ bool radio_update(radio_t* const radio);
  */
 void radio_switch_opmode(radio_t* const radio, const transceiver_mode_t mode);
 
+/**
+ * Switch to a new configuration mode.
+ * Return true if the mode was successfully switched.
+ */
+bool radio_set_config_mode(radio_t* const radio, const radio_config_mode_t mode);
+
 /**
  * Driver instance.
  */

From e57fbe6ee6f1f15233bd30c19851455d48daf566 Mon Sep 17 00:00:00 2001
From: Antoine van Gelder <antoine@greatscottgadgets.com>
Date: Mon, 22 Jun 2026 16:40:10 +0200
Subject: [PATCH 3/7] Add 'hackrf_open_mode()', 'hackrf_open_mode_by_serial()'
 and 'hackrf_device_list_open_mode()'

---
 firmware/hackrf_usb/hackrf_usb.c          |  2 +
 firmware/hackrf_usb/usb_api_transceiver.c | 36 +++++++++
 firmware/hackrf_usb/usb_api_transceiver.h |  6 ++
 host/libhackrf/src/hackrf.c               | 95 ++++++++++++++++++++---
 host/libhackrf/src/hackrf.h               | 64 +++++++++++++++
 5 files changed, 193 insertions(+), 10 deletions(-)

diff --git a/firmware/hackrf_usb/hackrf_usb.c b/firmware/hackrf_usb/hackrf_usb.c
index 4cdfbd14e..a228e6bb4 100644
--- a/firmware/hackrf_usb/hackrf_usb.c
+++ b/firmware/hackrf_usb/hackrf_usb.c
@@ -183,6 +183,8 @@ static usb_request_handler_fn vendor_request_handler[] = {
 	usb_vendor_request_read_radio_reg,
 	usb_vendor_request_get_buffer_size,
 	usb_vendor_request_lock_radio_reg,
+	usb_vendor_request_open,
+	usb_vendor_request_close,
 };
 
 static const uint32_t vendor_request_handler_count =
diff --git a/firmware/hackrf_usb/usb_api_transceiver.c b/firmware/hackrf_usb/usb_api_transceiver.c
index dbbbf661a..c694d9d43 100644
--- a/firmware/hackrf_usb/usb_api_transceiver.c
+++ b/firmware/hackrf_usb/usb_api_transceiver.c
@@ -486,6 +486,42 @@ usb_request_status_t usb_vendor_request_get_buffer_size(
 	return USB_REQUEST_STATUS_OK;
 }
 
+usb_request_status_t usb_vendor_request_open(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage)
+{
+	uint16_t usb_api_version;
+	radio_config_mode_t radio_config_mode;
+
+	if (stage == USB_TRANSFER_STAGE_SETUP) {
+		usb_api_version = endpoint->setup.value;
+		radio_config_mode = (radio_config_mode_t) endpoint->setup.index;
+
+		// TODO let device know we have a new libhackrf connection and its supported usb_api_version
+		(void) usb_api_version;
+
+		// switch bitstreams and update radio mode
+		if (!radio_set_config_mode(&radio, radio_config_mode)) {
+			return USB_REQUEST_STATUS_STALL;
+		}
+		usb_transfer_schedule_ack(endpoint->in);
+	}
+
+	return USB_REQUEST_STATUS_OK;
+}
+
+usb_request_status_t usb_vendor_request_close(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage)
+{
+	if (stage == USB_TRANSFER_STAGE_SETUP) {
+		// TODO do nothing for now
+		usb_transfer_schedule_ack(endpoint->in);
+	}
+
+	return USB_REQUEST_STATUS_OK;
+}
+
 /* clang-format off */
 
 // Which GPDMA channel to use.
diff --git a/firmware/hackrf_usb/usb_api_transceiver.h b/firmware/hackrf_usb/usb_api_transceiver.h
index a29dec118..a28b8514e 100644
--- a/firmware/hackrf_usb/usb_api_transceiver.h
+++ b/firmware/hackrf_usb/usb_api_transceiver.h
@@ -80,6 +80,12 @@ usb_request_status_t usb_vendor_request_set_rx_overrun_limit(
 usb_request_status_t usb_vendor_request_get_buffer_size(
 	usb_endpoint_t* const endpoint,
 	const usb_transfer_stage_t stage);
+usb_request_status_t usb_vendor_request_open(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage);
+usb_request_status_t usb_vendor_request_close(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage);
 
 void request_transceiver_mode(transceiver_mode_t mode);
 void transceiver_startup(transceiver_mode_t mode);
diff --git a/host/libhackrf/src/hackrf.c b/host/libhackrf/src/hackrf.c
index a3b90163f..fa6c7f84d 100644
--- a/host/libhackrf/src/hackrf.c
+++ b/host/libhackrf/src/hackrf.c
@@ -121,6 +121,8 @@ typedef enum {
 	HACKRF_VENDOR_REQUEST_RADIO_READ_REG = 60,
 	HACKRF_VENDOR_REQUEST_GET_BUFFER_SIZE = 61,
 	HACKRF_VENDOR_REQUEST_RADIO_LOCK_REG = 62,
+	HACKRF_VENDOR_REQUEST_OPEN = 63,
+	HACKRF_VENDOR_REQUEST_CLOSE = 64,
 } hackrf_vendor_request;
 
 #define USB_CONFIG_STANDARD 0x1
@@ -714,7 +716,10 @@ libusb_device_handle* hackrf_open_usb(const char* const desired_serial_number)
 	return usb_device;
 }
 
-static int hackrf_open_setup(libusb_device_handle* usb_device, hackrf_device** device)
+static int hackrf_open_setup(
+	enum radio_config_mode mode,
+	libusb_device_handle* usb_device,
+	hackrf_device** device)
 {
 	int result;
 	hackrf_device* lib_device;
@@ -796,6 +801,24 @@ static int hackrf_open_setup(libusb_device_handle* usb_device, hackrf_device** d
 		lib_device->buffer_size = 32768;
 	}
 
+	if (lib_device->usb_api_version >= 0x0113) {
+		// Send supported usb api version and requested configuration mode to device.
+		result = libusb_control_transfer(
+			lib_device->usb_device,
+			LIBUSB_ENDPOINT_OUT | LIBUSB_REQUEST_TYPE_VENDOR |
+				LIBUSB_RECIPIENT_DEVICE,
+			HACKRF_VENDOR_REQUEST_OPEN,
+			lib_device->usb_api_version,
+			(uint16_t) mode,
+			NULL,
+			0,
+			DEFAULT_REQUEST_TIMEOUT);
+		if (result != 0) {
+			last_libusb_error = result;
+			return HACKRF_ERROR_LIBUSB;
+		}
+	}
+
 	result = pthread_mutex_init(&lib_device->transfer_lock, NULL);
 	if (result != 0) {
 		free(lib_device);
@@ -834,7 +857,7 @@ static int hackrf_open_setup(libusb_device_handle* usb_device, hackrf_device** d
 	return HACKRF_SUCCESS;
 }
 
-int ADDCALL hackrf_open(hackrf_device** device)
+int ADDCALL hackrf_open_mode(const enum radio_config_mode mode, hackrf_device** device)
 {
 	libusb_device_handle* usb_device;
 
@@ -865,17 +888,18 @@ int ADDCALL hackrf_open(hackrf_device** device)
 		return HACKRF_ERROR_NOT_FOUND;
 	}
 
-	return hackrf_open_setup(usb_device, device);
+	return hackrf_open_setup(mode, usb_device, device);
 }
 
-int ADDCALL hackrf_open_by_serial(
+int ADDCALL hackrf_open_mode_by_serial(
+	const enum radio_config_mode mode,
 	const char* const desired_serial_number,
 	hackrf_device** device)
 {
 	libusb_device_handle* usb_device;
 
 	if (desired_serial_number == NULL) {
-		return hackrf_open(device);
+		return hackrf_open_mode(mode, device);
 	}
 
 	if (device == NULL) {
@@ -888,10 +912,11 @@ int ADDCALL hackrf_open_by_serial(
 		return HACKRF_ERROR_NOT_FOUND;
 	}
 
-	return hackrf_open_setup(usb_device, device);
+	return hackrf_open_setup(mode, usb_device, device);
 }
 
-int ADDCALL hackrf_device_list_open(
+int ADDCALL hackrf_device_list_open_mode(
+	const enum radio_config_mode mode,
 	hackrf_device_list_t* list,
 	int idx,
 	hackrf_device** device)
@@ -912,7 +937,30 @@ int ADDCALL hackrf_device_list_open(
 		return HACKRF_ERROR_LIBUSB;
 	}
 
-	return hackrf_open_setup(usb_device, device);
+	return hackrf_open_setup(mode, usb_device, device);
+}
+
+int ADDCALL hackrf_open(hackrf_device** device)
+{
+	return hackrf_open_mode(RADIO_CONFIG_STANDARD, device);
+}
+
+int ADDCALL hackrf_open_by_serial(
+	const char* const desired_serial_number,
+	hackrf_device** device)
+{
+	return hackrf_open_mode_by_serial(
+		RADIO_CONFIG_STANDARD,
+		desired_serial_number,
+		device);
+}
+
+int ADDCALL hackrf_device_list_open(
+	hackrf_device_list_t* list,
+	int idx,
+	hackrf_device** device)
+{
+	return hackrf_device_list_open_mode(RADIO_CONFIG_STANDARD, list, idx, device);
 }
 
 int ADDCALL hackrf_device_list_bus_sharing(hackrf_device_list_t* list, int idx)
@@ -2443,10 +2491,11 @@ int ADDCALL hackrf_stop_tx(hackrf_device* device)
 
 int ADDCALL hackrf_close(hackrf_device* device)
 {
-	int result1, result2;
+	int result1, result2, result3;
 
 	result1 = HACKRF_SUCCESS;
 	result2 = HACKRF_SUCCESS;
+	result3 = HACKRF_SUCCESS;
 
 	if (device != NULL) {
 		result1 = hackrf_stop_cmd(device);
@@ -2456,6 +2505,27 @@ int ADDCALL hackrf_close(hackrf_device* device)
 		 * also cancel any pending transmit/receive transfers.
 		 */
 		result2 = kill_transfer_thread(device);
+
+		if (device->usb_api_version >= 0x0113) {
+			/*
+			 * Let the device know it's been closed.
+			 */
+			result3 = libusb_control_transfer(
+				device->usb_device,
+				LIBUSB_ENDPOINT_OUT | LIBUSB_REQUEST_TYPE_VENDOR |
+					LIBUSB_RECIPIENT_DEVICE,
+				HACKRF_VENDOR_REQUEST_CLOSE,
+				0,
+				0,
+				NULL,
+				0,
+				DEFAULT_REQUEST_TIMEOUT);
+			if (result3 != 0) {
+				last_libusb_error = result3;
+				result3 = HACKRF_ERROR_LIBUSB;
+			}
+		}
+
 		if (device->usb_device != NULL) {
 			libusb_release_interface(device->usb_device, 0);
 			libusb_close(device->usb_device);
@@ -2474,7 +2544,12 @@ int ADDCALL hackrf_close(hackrf_device* device)
 	if (result2 != HACKRF_SUCCESS) {
 		return result2;
 	}
-	return result1;
+
+	if (result1 != HACKRF_SUCCESS) {
+		return result1;
+	}
+
+	return result3;
 }
 
 const char* ADDCALL hackrf_error_name(enum hackrf_error errcode)
diff --git a/host/libhackrf/src/hackrf.h b/host/libhackrf/src/hackrf.h
index 6cf71dd91..88035c909 100644
--- a/host/libhackrf/src/hackrf.h
+++ b/host/libhackrf/src/hackrf.h
@@ -946,6 +946,19 @@ enum clkin_ctrl_signal {
 	CLKIN_SIGNAL_P22 = 1,
 };
 
+/**
+ * HackRF Pro Radio Configuration Mode.
+ *
+ * Used by @ref hackrf_open, @ref hackrf_open_mode_by_serial and @ref hackrf_device_list_open_mode to set the active configuration mode.
+ */
+enum radio_config_mode {
+	RADIO_CONFIG_LEGACY = 0,
+	RADIO_CONFIG_STANDARD = 1,
+	RADIO_CONFIG_EXT_PRECISION_RX = 2,
+	RADIO_CONFIG_EXT_PRECISION_TX = 3,
+	RADIO_CONFIG_HALF_PRECISION = 4,
+};
+
 /**
  * Opaque struct for hackrf device info. Object can be created via @ref hackrf_open, @ref hackrf_device_list_open or @ref hackrf_open_by_serial and be destroyed via @ref hackrf_close
  * @ingroup device
@@ -1199,6 +1212,7 @@ extern ADDAPI hackrf_device_list_t* ADDCALL hackrf_device_list();
 
 /**
  * Open a @ref hackrf_device from a device list
+ * @deprecated this function has been replaced by @ref hackrf_device_list_open_mode
  * @param[in] list device list to open device from
  * @param[in] idx index of the device to open
  * @param[out] device device handle to open
@@ -1210,6 +1224,24 @@ extern ADDAPI int ADDCALL hackrf_device_list_open(
 	int idx,
 	hackrf_device** device);
 
+/**
+ * Open a @ref hackrf_device from a device list and initialize it to the given radio configuration mode.
+ *
+ * Modes other than RADIO_CONFIG_STANDARD are only supported on HackRF Pro hardware.
+ *
+ * @param[in] mode configuration mode. Defaults to RADIO_CONFIG_STANDARD. Available modes are defined in @ref radio_config_mode.
+ * @param[in] list device list to open device from
+ * @param[in] idx index of the device to open
+ * @param[out] device device handle to open
+ * @return @ref HACKRF_SUCCESS on success, @ref HACKRF_ERROR_INVALID_PARAM on invalid parameters or other @ref hackrf_error variant
+ * @ingroup device
+ */
+extern ADDAPI int ADDCALL hackrf_device_list_open_mode(
+	const enum radio_config_mode mode,
+	hackrf_device_list_t* list,
+	int idx,
+	hackrf_device** device);
+
 /**
  * Check if a listed HackRF device is sharing its USB bus with other devices.
  *
@@ -1231,14 +1263,30 @@ extern ADDAPI void ADDCALL hackrf_device_list_free(hackrf_device_list_t* list);
 
 /**
  * Open first available HackRF device
+ * @deprecated this function has been replaced by @ref hackrf_open_mode
  * @param[out] device device handle
  * @return @ref HACKRF_SUCCESS on success, @ref HACKRF_ERROR_INVALID_PARAM if @p device is NULL, @ref HACKRF_ERROR_NOT_FOUND if no HackRF devices are found or other @ref hackrf_error variant
  * @ingroup device
  */
 extern ADDAPI int ADDCALL hackrf_open(hackrf_device** device);
 
+/**
+ * Open first available HackRF device and initialize it to the given radio configuration mode.
+ *
+ * Modes other than RADIO_CONFIG_STANDARD are only supported on HackRF Pro hardware.
+ *
+ * @param[in] mode configuration mode. Defaults to RADIO_CONFIG_STANDARD. Available modes are defined in @ref radio_config_mode.
+ * @param[out] device device handle
+ * @return @ref HACKRF_SUCCESS on success, @ref HACKRF_ERROR_INVALID_PARAM if @p device is NULL, @ref HACKRF_ERROR_NOT_FOUND if no HackRF devices are found or other @ref hackrf_error variant
+ * @ingroup device
+ */
+extern ADDAPI int ADDCALL hackrf_open_mode(
+	const enum radio_config_mode mode,
+	hackrf_device** device);
+
 /**
  * Open HackRF device by serial number
+ * @deprecated this function has been replaced by @ref hackrf_open_mode_by_serial
  * @param[in] desired_serial_number serial number of device to open. If NULL then default to first device found.
  * @param[out] device device handle
  * @return @ref HACKRF_SUCCESS on success, @ref HACKRF_ERROR_INVALID_PARAM if @p device is NULL, @ref HACKRF_ERROR_NOT_FOUND if no HackRF devices are found or other @ref hackrf_error variant
@@ -1248,6 +1296,22 @@ extern ADDAPI int ADDCALL hackrf_open_by_serial(
 	const char* const desired_serial_number,
 	hackrf_device** device);
 
+/**
+ * Open HackRF device by serial number and initialize it to the given radio configuration mode.
+ *
+ * Modes other than RADIO_CONFIG_STANDARD are only supported on HackRF Pro hardware.
+ *
+ * @param[in] mode configuration mode. Defaults to RADIO_CONFIG_STANDARD. Available modes are defined in @ref radio_config_mode.
+ * @param[in] desired_serial_number serial number of device to open. If NULL then default to first device found.
+ * @param[out] device device handle
+ * @return @ref HACKRF_SUCCESS on success, @ref HACKRF_ERROR_INVALID_PARAM if @p device is NULL, @ref HACKRF_ERROR_NOT_FOUND if no HackRF devices are found or other @ref hackrf_error variant
+ * @ingroup device
+ */
+extern ADDAPI int ADDCALL hackrf_open_mode_by_serial(
+	const enum radio_config_mode mode,
+	const char* const desired_serial_number,
+	hackrf_device** device);
+
 /**
  * Close a previously opened device
  * @param[in] device device to close

From e03d4a14ef302467952d50346287f8f4d0508414 Mon Sep 17 00:00:00 2001
From: Antoine van Gelder <antoine@greatscottgadgets.com>
Date: Wed, 24 Jun 2026 11:03:24 +0200
Subject: [PATCH 4/7] Add 'hackrf_radio_set_mode()'

---
 firmware/hackrf_usb/CMakeLists.txt  |  1 +
 firmware/hackrf_usb/hackrf_usb.c    |  2 ++
 firmware/hackrf_usb/usb_api_radio.c | 41 +++++++++++++++++++++++++++++
 firmware/hackrf_usb/usb_api_radio.h | 29 ++++++++++++++++++++
 host/libhackrf/src/hackrf.c         | 25 ++++++++++++++++++
 host/libhackrf/src/hackrf.h         | 12 +++++++++
 6 files changed, 110 insertions(+)
 create mode 100644 firmware/hackrf_usb/usb_api_radio.c
 create mode 100644 firmware/hackrf_usb/usb_api_radio.h

diff --git a/firmware/hackrf_usb/CMakeLists.txt b/firmware/hackrf_usb/CMakeLists.txt
index 871e0909f..027fc97a8 100644
--- a/firmware/hackrf_usb/CMakeLists.txt
+++ b/firmware/hackrf_usb/CMakeLists.txt
@@ -60,6 +60,7 @@ set(SRC_M4
 	usb_api_spiflash.c
 	usb_api_transceiver.c
 	usb_api_operacake.c
+	usb_api_radio.c
 	usb_api_sweep.c
 	usb_api_selftest.c
 	usb_api_ui.c
diff --git a/firmware/hackrf_usb/hackrf_usb.c b/firmware/hackrf_usb/hackrf_usb.c
index a228e6bb4..8cfeabe85 100644
--- a/firmware/hackrf_usb/hackrf_usb.c
+++ b/firmware/hackrf_usb/hackrf_usb.c
@@ -75,6 +75,7 @@
 #include "usb_api_board_info.h"
 #include "usb_api_m0_state.h"
 #include "usb_api_operacake.h"
+#include "usb_api_radio.h"
 #include "usb_api_register.h"
 #include "usb_api_selftest.h"
 #include "usb_api_spiflash.h"
@@ -185,6 +186,7 @@ static usb_request_handler_fn vendor_request_handler[] = {
 	usb_vendor_request_lock_radio_reg,
 	usb_vendor_request_open,
 	usb_vendor_request_close,
+	usb_vendor_request_set_radio_mode,
 };
 
 static const uint32_t vendor_request_handler_count =
diff --git a/firmware/hackrf_usb/usb_api_radio.c b/firmware/hackrf_usb/usb_api_radio.c
new file mode 100644
index 000000000..e85c7d987
--- /dev/null
+++ b/firmware/hackrf_usb/usb_api_radio.c
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2026 Great Scott Gadgets <info@greatscottgadgets.com>
+ *
+ * This file is part of HackRF.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include <radio.h>
+#include <usb_request.h>
+#include <usb_type.h>
+
+#include "usb_queue.h"
+
+usb_request_status_t usb_vendor_request_set_radio_mode(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage)
+{
+	if (stage == USB_TRANSFER_STAGE_SETUP) {
+		radio_config_mode_t mode = endpoint->setup.value;
+		if (!radio_set_config_mode(&radio, mode)) {
+			return USB_REQUEST_STATUS_STALL;
+		}
+		usb_transfer_schedule_ack(endpoint->in);
+	}
+
+	return USB_REQUEST_STATUS_OK;
+}
diff --git a/firmware/hackrf_usb/usb_api_radio.h b/firmware/hackrf_usb/usb_api_radio.h
new file mode 100644
index 000000000..9eb098d0d
--- /dev/null
+++ b/firmware/hackrf_usb/usb_api_radio.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright 2026 Great Scott Gadgets <info@greatscottgadgets.com>
+ *
+ * This file is part of HackRF.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#pragma once
+
+#include <usb_request.h>
+#include <usb_type.h>
+
+usb_request_status_t usb_vendor_request_set_radio_mode(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage);
diff --git a/host/libhackrf/src/hackrf.c b/host/libhackrf/src/hackrf.c
index fa6c7f84d..c9d67c905 100644
--- a/host/libhackrf/src/hackrf.c
+++ b/host/libhackrf/src/hackrf.c
@@ -123,6 +123,7 @@ typedef enum {
 	HACKRF_VENDOR_REQUEST_RADIO_LOCK_REG = 62,
 	HACKRF_VENDOR_REQUEST_OPEN = 63,
 	HACKRF_VENDOR_REQUEST_CLOSE = 64,
+	HACKRF_VENDOR_REQUEST_RADIO_SET_MODE = 65,
 } hackrf_vendor_request;
 
 #define USB_CONFIG_STANDARD 0x1
@@ -3677,6 +3678,30 @@ int ADDCALL hackrf_radio_lock_register(
 	return HACKRF_SUCCESS;
 }
 
+int ADDCALL hackrf_radio_set_mode(hackrf_device* device, const enum radio_config_mode mode)
+{
+	USB_API_REQUIRED(device, 0x0113);
+	int result;
+
+	result = libusb_control_transfer(
+		device->usb_device,
+		LIBUSB_ENDPOINT_OUT | LIBUSB_REQUEST_TYPE_VENDOR |
+			LIBUSB_RECIPIENT_DEVICE,
+		HACKRF_VENDOR_REQUEST_RADIO_SET_MODE,
+		mode,
+		0,
+		NULL,
+		0,
+		DEFAULT_REQUEST_TIMEOUT);
+
+	if (result != 0) {
+		last_libusb_error = result;
+		return HACKRF_ERROR_LIBUSB;
+	}
+
+	return HACKRF_SUCCESS;
+}
+
 #ifdef __cplusplus
 } // __cplusplus defined.
 #endif
diff --git a/host/libhackrf/src/hackrf.h b/host/libhackrf/src/hackrf.h
index 88035c909..5d2a27a2c 100644
--- a/host/libhackrf/src/hackrf.h
+++ b/host/libhackrf/src/hackrf.h
@@ -2463,6 +2463,18 @@ extern ADDAPI int ADDCALL hackrf_radio_lock_register(
 	const uint8_t register_number,
 	const bool register_locked);
 
+/**
+ * Switches the radio configuration mode.
+ *
+ * @param[in] device device to configure
+ * @param[in] mode configuration mode. Defaults to RADIO_CONFIG_LEGACY. Available modes are defined in @ref radio_config_mode.
+ * @return @ref HACKRF_SUCCESS on success or @ref hackrf_error variant
+ * @ingroup configuration
+ */
+extern ADDAPI int ADDCALL hackrf_radio_set_mode(
+	hackrf_device* device,
+	const enum radio_config_mode mode);
+
 #ifdef __cplusplus
 } // __cplusplus defined.
 #endif

From 161f6275f6a36d1658c041635676f3051b4f1ba2 Mon Sep 17 00:00:00 2001
From: Antoine van Gelder <antoine@greatscottgadgets.com>
Date: Mon, 29 Jun 2026 15:03:12 +0200
Subject: [PATCH 5/7] Remove 'RADIO_CONFIG_LEGACY'

---
 firmware/common/radio.c     |  2 --
 firmware/common/radio.h     | 10 ++++------
 host/libhackrf/src/hackrf.h | 11 +++++------
 3 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/firmware/common/radio.c b/firmware/common/radio.c
index 9755a02db..d9a9f80b7 100644
--- a/firmware/common/radio.c
+++ b/firmware/common/radio.c
@@ -957,7 +957,6 @@ bool radio_set_config_mode(radio_t* const radio, const radio_config_mode_t mode)
 {
 	// Check if the requested mode is supported.
 	switch (mode) {
-	case RADIO_CONFIG_LEGACY:
 	case RADIO_CONFIG_STANDARD:
 		// supported on all boards
 		break;
@@ -984,7 +983,6 @@ bool radio_set_config_mode(radio_t* const radio, const radio_config_mode_t mode)
 	if (IS_PRALINE) {
 		fpga_bitstream_index_t bitstream_index;
 		switch (mode) {
-		case RADIO_CONFIG_LEGACY:
 		case RADIO_CONFIG_STANDARD:
 			bitstream_index = FPGA_BITSTREAM_STANDARD;
 			break;
diff --git a/firmware/common/radio.h b/firmware/common/radio.h
index ba4ced388..df7b6462d 100644
--- a/firmware/common/radio.h
+++ b/firmware/common/radio.h
@@ -41,14 +41,12 @@ typedef enum {
 } radio_error_t;
 
 /* radio configuration modes */
-// TODO are we sure we need a legacy mode?
 typedef enum {
-	RADIO_CONFIG_LEGACY = 0,
-	RADIO_CONFIG_STANDARD = 1,
+	RADIO_CONFIG_STANDARD = 0,
 #ifdef IS_PRALINE
-	RADIO_CONFIG_EXT_PRECISION_RX = 2,
-	RADIO_CONFIG_EXT_PRECISION_TX = 3,
-	RADIO_CONFIG_HALF_PRECISION = 4,
+	RADIO_CONFIG_EXT_PRECISION_RX = 1,
+	RADIO_CONFIG_EXT_PRECISION_TX = 2,
+	RADIO_CONFIG_HALF_PRECISION = 3,
 #endif
 } radio_config_mode_t;
 
diff --git a/host/libhackrf/src/hackrf.h b/host/libhackrf/src/hackrf.h
index 5d2a27a2c..60666a3a3 100644
--- a/host/libhackrf/src/hackrf.h
+++ b/host/libhackrf/src/hackrf.h
@@ -952,11 +952,10 @@ enum clkin_ctrl_signal {
  * Used by @ref hackrf_open, @ref hackrf_open_mode_by_serial and @ref hackrf_device_list_open_mode to set the active configuration mode.
  */
 enum radio_config_mode {
-	RADIO_CONFIG_LEGACY = 0,
-	RADIO_CONFIG_STANDARD = 1,
-	RADIO_CONFIG_EXT_PRECISION_RX = 2,
-	RADIO_CONFIG_EXT_PRECISION_TX = 3,
-	RADIO_CONFIG_HALF_PRECISION = 4,
+	RADIO_CONFIG_STANDARD = 0,
+	RADIO_CONFIG_EXT_PRECISION_RX = 1,
+	RADIO_CONFIG_EXT_PRECISION_TX = 2,
+	RADIO_CONFIG_HALF_PRECISION = 3,
 };
 
 /**
@@ -2467,7 +2466,7 @@ extern ADDAPI int ADDCALL hackrf_radio_lock_register(
  * Switches the radio configuration mode.
  *
  * @param[in] device device to configure
- * @param[in] mode configuration mode. Defaults to RADIO_CONFIG_LEGACY. Available modes are defined in @ref radio_config_mode.
+ * @param[in] mode configuration mode. Defaults to RADIO_CONFIG_STANDARD. Available modes are defined in @ref radio_config_mode.
  * @return @ref HACKRF_SUCCESS on success or @ref hackrf_error variant
  * @ingroup configuration
  */

From 2f4fa473fc0fd08f94dfede5cc72ff5ac817bc87 Mon Sep 17 00:00:00 2001
From: Antoine van Gelder <antoine@greatscottgadgets.com>
Date: Tue, 16 Jun 2026 14:35:57 +0200
Subject: [PATCH 6/7] libhackrf: add 'hackrf_radio_set_frequency()',
 'hackrf_radio_set_frequency_explicit()' and 'hackrf_radio_set_sample_rate()'

---
 firmware/hackrf_usb/hackrf_usb.c    |   3 +
 firmware/hackrf_usb/usb_api_radio.c | 100 ++++++++++++++++++
 firmware/hackrf_usb/usb_api_radio.h |  12 +++
 host/libhackrf/src/hackrf.c         | 156 ++++++++++++++++++++++++++++
 host/libhackrf/src/hackrf.h         | 107 ++++++++++++++++++-
 5 files changed, 375 insertions(+), 3 deletions(-)

diff --git a/firmware/hackrf_usb/hackrf_usb.c b/firmware/hackrf_usb/hackrf_usb.c
index 8cfeabe85..95bfb6e52 100644
--- a/firmware/hackrf_usb/hackrf_usb.c
+++ b/firmware/hackrf_usb/hackrf_usb.c
@@ -187,6 +187,9 @@ static usb_request_handler_fn vendor_request_handler[] = {
 	usb_vendor_request_open,
 	usb_vendor_request_close,
 	usb_vendor_request_set_radio_mode,
+	usb_vendor_request_set_radio_frequency,
+	usb_vendor_request_set_radio_frequency_explicit,
+	usb_vendor_request_set_radio_sample_rate,
 };
 
 static const uint32_t vendor_request_handler_count =
diff --git a/firmware/hackrf_usb/usb_api_radio.c b/firmware/hackrf_usb/usb_api_radio.c
index e85c7d987..13c547cfe 100644
--- a/firmware/hackrf_usb/usb_api_radio.c
+++ b/firmware/hackrf_usb/usb_api_radio.c
@@ -19,6 +19,10 @@
  * Boston, MA 02110-1301, USA.
  */
 
+#include <stddef.h>
+#include <stdint.h>
+
+#include <fixed_point.h>
 #include <radio.h>
 #include <usb_request.h>
 #include <usb_type.h>
@@ -39,3 +43,99 @@ usb_request_status_t usb_vendor_request_set_radio_mode(
 
 	return USB_REQUEST_STATUS_OK;
 }
+
+usb_request_status_t usb_vendor_request_set_radio_frequency(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage)
+{
+	static fp_40_24_t hz_param;
+
+	if (stage == USB_TRANSFER_STAGE_SETUP) {
+		usb_transfer_schedule_block(
+			endpoint->out,
+			&hz_param,
+			sizeof(fp_40_24_t),
+			NULL,
+			NULL);
+	} else if (stage == USB_TRANSFER_STAGE_DATA) {
+		radio_reg_write(&radio, RADIO_BANK_ACTIVE, RADIO_FREQUENCY_RF, hz_param);
+		radio_reg_write(
+			&radio,
+			RADIO_BANK_ACTIVE,
+			RADIO_FREQUENCY_IF,
+			RADIO_UNSET);
+		radio_reg_write(
+			&radio,
+			RADIO_BANK_ACTIVE,
+			RADIO_FREQUENCY_LO,
+			RADIO_UNSET);
+		radio_reg_write(
+			&radio,
+			RADIO_BANK_ACTIVE,
+			RADIO_IMAGE_REJECT,
+			RADIO_UNSET);
+		usb_transfer_schedule_ack(endpoint->in);
+	}
+
+	return USB_REQUEST_STATUS_OK;
+}
+
+usb_request_status_t usb_vendor_request_set_radio_frequency_explicit(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage)
+{
+	static struct {
+		fp_40_24_t if_freq_hz;
+		fp_40_24_t lo_freq_hz;
+		uint8_t path;
+	} params;
+
+	if (stage == USB_TRANSFER_STAGE_SETUP) {
+		usb_transfer_schedule_block(
+			endpoint->out,
+			&params,
+			sizeof(params),
+			NULL,
+			NULL);
+	} else if (stage == USB_TRANSFER_STAGE_DATA) {
+		radio_reg_write(
+			&radio,
+			RADIO_BANK_ACTIVE,
+			RADIO_FREQUENCY_IF,
+			params.if_freq_hz);
+		radio_reg_write(
+			&radio,
+			RADIO_BANK_ACTIVE,
+			RADIO_FREQUENCY_LO,
+			params.lo_freq_hz);
+		radio_reg_write(
+			&radio,
+			RADIO_BANK_ACTIVE,
+			RADIO_IMAGE_REJECT,
+			params.path);
+		usb_transfer_schedule_ack(endpoint->in);
+	}
+
+	return USB_REQUEST_STATUS_OK;
+}
+
+usb_request_status_t usb_vendor_request_set_radio_sample_rate(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage)
+{
+	static fp_28_36_t sps_param;
+
+	if (stage == USB_TRANSFER_STAGE_SETUP) {
+		usb_transfer_schedule_block(
+			endpoint->out,
+			&sps_param,
+			sizeof(fp_28_36_t),
+			NULL,
+			NULL);
+	} else if (stage == USB_TRANSFER_STAGE_DATA) {
+		radio_reg_write(&radio, RADIO_BANK_ACTIVE, RADIO_SAMPLE_RATE, sps_param);
+		usb_transfer_schedule_ack(endpoint->in);
+	}
+
+	return USB_REQUEST_STATUS_OK;
+}
diff --git a/firmware/hackrf_usb/usb_api_radio.h b/firmware/hackrf_usb/usb_api_radio.h
index 9eb098d0d..c8940c112 100644
--- a/firmware/hackrf_usb/usb_api_radio.h
+++ b/firmware/hackrf_usb/usb_api_radio.h
@@ -27,3 +27,15 @@
 usb_request_status_t usb_vendor_request_set_radio_mode(
 	usb_endpoint_t* const endpoint,
 	const usb_transfer_stage_t stage);
+
+usb_request_status_t usb_vendor_request_set_radio_frequency(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage);
+
+usb_request_status_t usb_vendor_request_set_radio_frequency_explicit(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage);
+
+usb_request_status_t usb_vendor_request_set_radio_sample_rate(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage);
diff --git a/host/libhackrf/src/hackrf.c b/host/libhackrf/src/hackrf.c
index c9d67c905..06c96f838 100644
--- a/host/libhackrf/src/hackrf.c
+++ b/host/libhackrf/src/hackrf.c
@@ -124,6 +124,9 @@ typedef enum {
 	HACKRF_VENDOR_REQUEST_OPEN = 63,
 	HACKRF_VENDOR_REQUEST_CLOSE = 64,
 	HACKRF_VENDOR_REQUEST_RADIO_SET_MODE = 65,
+	HACKRF_VENDOR_REQUEST_RADIO_SET_FREQUENCY = 66,
+	HACKRF_VENDOR_REQUEST_RADIO_SET_FREQUENCY_EXPLICIT = 67,
+	HACKRF_VENDOR_REQUEST_RADIO_SET_SAMPLE_RATE = 68,
 } hackrf_vendor_request;
 
 #define USB_CONFIG_STANDARD 0x1
@@ -3702,6 +3705,159 @@ int ADDCALL hackrf_radio_set_mode(hackrf_device* device, const enum radio_config
 	return HACKRF_SUCCESS;
 }
 
+int ADDCALL hackrf_str_to_fp64(const uint8_t Qn, const char* str, uint64_t* const value)
+{
+	uint64_t m = 0;
+	uint64_t n = 0;
+	uint64_t div = 1;
+	uint64_t div_max = ceil((double) Qn * log10(2.0)) * 10;
+
+	// validate input
+	char* endptr;
+	strtod(str, &endptr);
+	if (endptr == str || *endptr != '\0') {
+		return HACKRF_ERROR_INVALID_PARAM;
+	}
+
+	// parse integer component
+	for (; (*str >= '0') && (*str <= '9'); str++) {
+		m = (m * 10) + (*str - '0');
+	}
+	*value = (m << Qn);
+
+	if (*str != '.') {
+		return HACKRF_SUCCESS;
+	}
+	str++;
+
+	// parse fractional component
+	for (; (*str >= '0') && (*str <= '9') && (div < div_max); str++) {
+		n = (n * 10) + (*str - '0');
+		div *= 10;
+	}
+
+	if (div == 1) {
+		return HACKRF_SUCCESS;
+	}
+
+	*value += ((n << Qn) + (div / 2)) / div;
+
+	return HACKRF_SUCCESS;
+}
+
+int ADDCALL hackrf_radio_set_frequency(hackrf_device* device, const fp_40_24_t freq_hz)
+{
+	USB_API_REQUIRED(device, 0x0113);
+	uint64_t set_freq_fp_param;
+	uint8_t length;
+	int result;
+
+	// serialize parameters
+	set_freq_fp_param = TO_LE64(freq_hz);
+	length = sizeof(uint64_t);
+
+	result = libusb_control_transfer(
+		device->usb_device,
+		LIBUSB_ENDPOINT_OUT | LIBUSB_REQUEST_TYPE_VENDOR |
+			LIBUSB_RECIPIENT_DEVICE,
+		HACKRF_VENDOR_REQUEST_RADIO_SET_FREQUENCY,
+		0,
+		0,
+		(unsigned char*) &set_freq_fp_param,
+		length,
+		DEFAULT_REQUEST_TIMEOUT);
+
+	if (result < length) {
+		last_libusb_error = result;
+		return HACKRF_ERROR_LIBUSB;
+	}
+
+	return HACKRF_SUCCESS;
+}
+
+int ADDCALL hackrf_radio_set_frequency_explicit(
+	hackrf_device* device,
+	const fp_40_24_t if_freq_hz,
+	const fp_40_24_t lo_freq_hz,
+	const enum rf_path_filter path)
+{
+	struct {
+		fp_40_24_t if_freq_hz;
+		fp_40_24_t lo_freq_hz;
+		uint8_t path;
+	} params;
+
+	uint8_t length;
+	int result;
+
+	// TODO are these values still correct for HackRF Pro ?
+	if (FP_FREQ_HZ(if_freq_hz) < 2000000000 || FP_FREQ_HZ(if_freq_hz) > 3000000000) {
+		return HACKRF_ERROR_INVALID_PARAM;
+	}
+
+	// TODO are these values still correct for HackRF Pro ?
+	if ((path != RF_PATH_FILTER_BYPASS) &&
+	    (FP_FREQ_HZ(lo_freq_hz) < 84375000 || FP_FREQ_HZ(lo_freq_hz) > 5400000000)) {
+		return HACKRF_ERROR_INVALID_PARAM;
+	}
+
+	if (path > 2) {
+		return HACKRF_ERROR_INVALID_PARAM;
+	}
+
+	params.if_freq_hz = TO_LE(if_freq_hz);
+	params.lo_freq_hz = TO_LE(lo_freq_hz);
+	params.path = (uint8_t) path;
+	length = sizeof(params);
+
+	result = libusb_control_transfer(
+		device->usb_device,
+		LIBUSB_ENDPOINT_OUT | LIBUSB_REQUEST_TYPE_VENDOR |
+			LIBUSB_RECIPIENT_DEVICE,
+		HACKRF_VENDOR_REQUEST_RADIO_SET_FREQUENCY_EXPLICIT,
+		0,
+		0,
+		(unsigned char*) &params,
+		length,
+		DEFAULT_REQUEST_TIMEOUT);
+
+	if (result < length) {
+		last_libusb_error = result;
+		return HACKRF_ERROR_LIBUSB;
+	} else {
+		return HACKRF_SUCCESS;
+	}
+}
+
+int ADDCALL hackrf_radio_set_sample_rate(hackrf_device* device, const fp_28_36_t freq_hz)
+{
+	USB_API_REQUIRED(device, 0x0113);
+	uint64_t set_sr_fp_param;
+	uint8_t length;
+	int result;
+
+	set_sr_fp_param = TO_LE64(freq_hz);
+	length = sizeof(uint64_t);
+
+	result = libusb_control_transfer(
+		device->usb_device,
+		LIBUSB_ENDPOINT_OUT | LIBUSB_REQUEST_TYPE_VENDOR |
+			LIBUSB_RECIPIENT_DEVICE,
+		HACKRF_VENDOR_REQUEST_RADIO_SET_SAMPLE_RATE,
+		0,
+		0,
+		(unsigned char*) &set_sr_fp_param,
+		length,
+		DEFAULT_REQUEST_TIMEOUT);
+
+	if (result < length) {
+		last_libusb_error = result;
+		return HACKRF_ERROR_LIBUSB;
+	}
+
+	return HACKRF_SUCCESS;
+}
+
 #ifdef __cplusplus
 } // __cplusplus defined.
 #endif
diff --git a/host/libhackrf/src/hackrf.h b/host/libhackrf/src/hackrf.h
index 60666a3a3..699f5d141 100644
--- a/host/libhackrf/src/hackrf.h
+++ b/host/libhackrf/src/hackrf.h
@@ -23,6 +23,7 @@ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSI
 
 #pragma once
 
+#include <math.h>
 #include <stdint.h>
 #include <sys/types.h>
 #include <stdbool.h> // for bool
@@ -1815,7 +1816,8 @@ extern ADDAPI int ADDCALL hackrf_usb_api_version_read(
  * Simple (auto) tuning via specifying a center frequency in Hz
  * 
  * This setting is not exact and depends on the PLL settings. Exact resolution is not determined, but the actual tuned frequency will be queryable in the future.
- * 
+ *
+ * @deprecated this function has been replaced by @ref hackrf_radio_set_frequency
  * @param device device to tune
  * @param freq_hz center frequency in Hz. Defaults to 900MHz. Should be in range 1-6000MHz, but 0-7250MHz is possible. The resolution is ~50Hz, I could not find the exact number.
  * @return @ref HACKRF_SUCCESS on success or @ref hackrf_error variant
@@ -1827,7 +1829,8 @@ extern ADDAPI int ADDCALL hackrf_set_freq(hackrf_device* device, const uint64_t
  * Set the center frequency via explicit tuning
  * 
  * Center frequency is set to \f$f_{center} = f_{IF} + k\cdot f_{LO}\f$ where \f$k\in\left\{-1; 0; 1\right\}\f$, depending on the value of @p path. See the documentation of @ref rf_path_filter for details
- * 
+ *
+ * @deprecated this function has been replaced by @ref hackrf_radio_set_frequency_explicit 
  * @param device device to tune
  * @param if_freq_hz tuning frequency of the MAX2837 transceiver IC in Hz. Must be in the range of 2150-2750MHz
  * @param lo_freq_hz tuning frequency of the RFFC5072 mixer/synthesizer IC in Hz. Must be in the range 84.375-5400MHz, defaults to 1000MHz. No effect if @p path is set to @ref RF_PATH_FILTER_BYPASS
@@ -1848,7 +1851,8 @@ extern ADDAPI int ADDCALL hackrf_set_freq_explicit(
  * 
  * This function sets the sample rate by specifying a clock frequency in Hz and a divider, so the resulting sample rate will be @p freq_hz / @p divider.
  * This function also sets the baseband filter bandwidth to a value \f$ \le 0.75 \cdot F_s \f$, so any calls to @ref hackrf_set_baseband_filter_bandwidth should only be made after this.
- * 
+ *
+ * @deprecated this function has been replaced by @ref hackrf_radio_set_sample_rate
  * @param device device to configure
  * @param freq_hz sample rate base frequency in Hz
  * @param divider frequency divider. Must be in the range 1-31
@@ -1866,6 +1870,7 @@ extern ADDAPI int ADDCALL hackrf_set_sample_rate_manual(
  * Sample rate should be in the range 2-20MHz, with the default being 10MHz. Lower & higher values are technically possible, but the performance is not guaranteed.
  * This function also sets the baseband filter bandwidth to a value \f$ \le 0.75 \cdot F_s \f$, so any calls to @ref hackrf_set_baseband_filter_bandwidth should only be made after this.
  * 
+ * @deprecated this function has been replaced by @ref hackrf_radio_set_sample_rate
  * @param device device to configure
  * @param freq_hz sample rate frequency in Hz. Should be in the range 2-20MHz
  * @return @ref HACKRF_SUCCESS on success or @ref hackrf_error variant
@@ -2474,6 +2479,102 @@ extern ADDAPI int ADDCALL hackrf_radio_set_mode(
 	hackrf_device* device,
 	const enum radio_config_mode mode);
 
+/**
+ * 40.24 Fixed-point type.
+ *
+ * Used by @ref hackrf_radio_set_frequency and @ref hackrf_radio_set_frequency_explicit
+ * to represent a fractional tuning frequency.
+ */
+typedef uint64_t fp_40_24_t;
+
+/**
+ * 28.36 Fixed-point type.
+ *
+ * Used by @ref hackrf_radio_set_sample_rate to represent a fractional sample rate.
+ */
+typedef uint64_t fp_28_36_t;
+
+/**
+ * Convert an integer frequency value to its corresponding fixed-point value.
+ */
+#define FREQ_FP_HZ(u64) ((uint64_t) u64 << 24)
+
+/**
+ * Convert an integer sample rate value to its corresponding fixed-point value.
+ */
+#define SR_FP_HZ(u64) ((uint64_t) u64 << 36)
+
+/**
+ * Convert a fixed-point frequency value to its corresponding integer value, rounding up to the nearest integer.
+ *
+ */
+#define FP_FREQ_HZ(u64) (((uint64_t) u64 + ((1ULL << 24) - 1)) >> 24)
+
+/**
+ * Convert a fixed-point sample rate value to its corresponding integer value, rounding up to the nearest integer.
+ */
+#define FP_SR_HZ(u64) (((uint64_t) u64 + ((1ULL << 36) - 1)) >> 36)
+
+/**
+ * Convert ASCII string to a 64 bit fixed-point number with a given number of bits of accuracy.
+ *
+ * @param[in] str string to parse
+ * @param[in] Qn  number of bits to use for fractional part
+ * @param[out] value  converted value
+ * @return @ref HACKRF_SUCCESS on success or @ref hackrf_error variant
+ * @ingroup configuration
+ */
+extern ADDAPI int ADDCALL hackrf_str_to_fp64(
+	const uint8_t Qn,
+	const char* str,
+	uint64_t* const value);
+
+/**
+ * Set the radio center frequency to a fractional, fixed-point value.
+ *
+ * @param[in] device device to tune
+ * @param[in] hz center frequency in Hz
+ * @return @ref HACKRF_SUCCESS on success or @ref hackrf_error variant
+ * @ingroup configuration
+ */
+extern ADDAPI int ADDCALL hackrf_radio_set_frequency(
+	hackrf_device* device,
+	const fp_40_24_t freq_hz);
+
+/**
+ * Set the radio center frequency to via explicit tuning.
+ *
+ * Center frequency is set to \f$f_{center} = f_{IF} + k\cdot f_{LO}\f$ where \f$k\in\left\{-1; 0; 1\right\}\f$, depending on the value of @p path. See the documentation of @ref rf_path_filter for details
+ *
+ * @param device device to tune
+ * TODO are these values still applicable for HackRF Pro ?
+ * @param if_freq_hz tuning frequency of the MAX2837 transceiver IC in Hz. Must be in the range of 2150-2750MHz
+ * TODO are these values still applicable for HackRF Pro ?
+ * @param lo_freq_hz tuning frequency of the RFFC5072 mixer/synthesizer IC in Hz. Must be in the range 84.375-5400MHz, defaults to 1000MHz. No effect if @p path is set to @ref RF_PATH_FILTER_BYPASS
+ * @param path filter path for mixer. See the documentation for @ref rf_path_filter for details
+ * @return @ref HACKRF_SUCCESS on success or @ref hackrf_error variant
+ * @ingroup configuration
+ */
+extern ADDAPI int ADDCALL hackrf_radio_set_frequency_explicit(
+	hackrf_device* device,
+	const fp_40_24_t if_freq_hz,
+	const fp_40_24_t lo_freq_hz,
+	const enum rf_path_filter path);
+
+/**
+ * Set the radio sample rate to a fractional, fixed-point value.
+ *
+ * This function does not automatically configure the baseband filter bandwidth, so any calls to this function should be followed by @ref hackrf_set_baseband_filter_bandwidth should it require adjustment.
+ *
+ * @param[in] device device to configure
+ * @param[in] sps samples per second
+ * @return @ref HACKRF_SUCCESS on success or @ref hackrf_error variant
+ * @ingroup configuration
+ */
+extern ADDAPI int ADDCALL hackrf_radio_set_sample_rate(
+	hackrf_device* device,
+	const fp_28_36_t freq_hz);
+
 #ifdef __cplusplus
 } // __cplusplus defined.
 #endif

From 754425aa3501c22f95f17278c2f3d511aba849ee Mon Sep 17 00:00:00 2001
From: Antoine van Gelder <antoine@greatscottgadgets.com>
Date: Tue, 23 Jun 2026 12:04:17 +0200
Subject: [PATCH 7/7] libhackrf: fallback to original code path for new_host ->
 old_firmware

---
 host/libhackrf/src/hackrf.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/host/libhackrf/src/hackrf.c b/host/libhackrf/src/hackrf.c
index 06c96f838..dc59adc7b 100644
--- a/host/libhackrf/src/hackrf.c
+++ b/host/libhackrf/src/hackrf.c
@@ -204,6 +204,8 @@ static const max2837_ft_t max2837_ft[] = {
 	if (device->usb_api_version < version) \
 		return HACKRF_ERROR_USB_API_VERSION;
 
+#define USB_API_REQUIRED_OR(device, version) if (device->usb_api_version < version)
+
 static const uint16_t hackrf_usb_vid = 0x1d50;
 static const uint16_t hackrf_jawbreaker_usb_pid = 0x604b;
 static const uint16_t hackrf_one_usb_pid = 0x6089;
@@ -3747,7 +3749,11 @@ int ADDCALL hackrf_str_to_fp64(const uint8_t Qn, const char* str, uint64_t* cons
 
 int ADDCALL hackrf_radio_set_frequency(hackrf_device* device, const fp_40_24_t freq_hz)
 {
-	USB_API_REQUIRED(device, 0x0113);
+	USB_API_REQUIRED_OR(device, 0x0113)
+	{
+		return hackrf_set_freq(device, FP_FREQ_HZ(freq_hz));
+	}
+
 	uint64_t set_freq_fp_param;
 	uint8_t length;
 	int result;
@@ -3781,6 +3787,15 @@ int ADDCALL hackrf_radio_set_frequency_explicit(
 	const fp_40_24_t lo_freq_hz,
 	const enum rf_path_filter path)
 {
+	USB_API_REQUIRED_OR(device, 0x0113)
+	{
+		return hackrf_set_freq_explicit(
+			device,
+			FP_FREQ_HZ(if_freq_hz),
+			FP_FREQ_HZ(lo_freq_hz),
+			path);
+	}
+
 	struct {
 		fp_40_24_t if_freq_hz;
 		fp_40_24_t lo_freq_hz;
@@ -3831,7 +3846,11 @@ int ADDCALL hackrf_radio_set_frequency_explicit(
 
 int ADDCALL hackrf_radio_set_sample_rate(hackrf_device* device, const fp_28_36_t freq_hz)
 {
-	USB_API_REQUIRED(device, 0x0113);
+	USB_API_REQUIRED_OR(device, 0x0113)
+	{
+		return hackrf_set_sample_rate(device, (double) freq_hz / (1ULL << 36));
+	}
+
 	uint64_t set_sr_fp_param;
 	uint8_t length;
 	int result;